Select the place where you will display you tree and also measure the height of ceiling. Always the height should be less then 1 foot compare to the height of ceiling.
Run your fingers along the needles and give the tree a shake. If the tree is fresh, the needles should be pliable and no more than ten should fall off.
Make sure the base of the tree is straight and at least six inches long, so it will fit easily into the tree stand.
Reference :
Artificial Christmas Trees